netdev - Re: [PATCH 2/2] move unneeded data to initdata section

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20071115151429.GC22825@uranus.ravnborg.org>
Date:	Thu, 15 Nov 2007 16:14:29 +0100
From:	Sam Ravnborg <sam@...nborg.org>
To:	"Denis V. Lunev" <den@...ru>
Cc:	"Eric W. Biederman" <ebiederm@...ssion.com>,
	"Denis V. Lunev" <den@...nvz.org>, davem@...emloft.net,
	containers@...ts.osdl.org, netdev@...r.kernel.org, clg@...ibm.com,
	benjamin.thery@...l.net
Subject: Re: [PATCH 2/2] move unneeded data to initdata section

On Thu, Nov 15, 2007 at 05:42:04PM +0300, Denis V. Lunev wrote:
> Eric W. Biederman wrote:
> > "Denis V. Lunev" <den@...nvz.org> writes:
> > 
> >> This patch reverts Eric's commit 2b008b0a8e96b726c603c5e1a5a7a509b5f61e35
> >>
> >> It diets .text & .data section of the kernel if CONFIG_NET_NS is not set.
> >> This is safe after list operations cleanup.
> > 
> > Ok.  This patch is technically safe because none of the touched
> > code can live in a module and so we never touch the exit code path.
> > 
> > However in the general case and as a code idiom this __net_initdata
> > on struct pernet_operations is fundamentally horribly broken.
> > 
> > Look at what happens if we use this idiom in module.  There
> > is only one definition of __initdata ".init.data".  The module
> > loader places all sections that begin with .init in a region of
> > memory that will be discarded after module initialization.  
> 
> nothing is discarded after module load. Though, I can be wrong. Could
> you point me to the exact place?
If __initdata is not discarded after module load then we should do it.
There is no reason to waste __initdata RAM when the module is loaded.

	Sam
-
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html